Solution composition and polymer light-emitting device

ABSTRACT

To provide a solution composition having a significantly high viscosity comprising one or more solvent(s) and one or more polymer(s) having a polystyrene-reduced Z-average molecular weight of 5.0×10 4  to 5.0×10 6 , and the solution composition allows to easily obtain a film having a favorable film formability and high uniformity.

CROSS REFERENCE TO RELATED APPLICATION

This is a divisional application of U.S. application Ser. No. 11/575,755filed Aug. 22, 2007, which is a 371 of PCT/JP05/019257 filed Oct. 13,2005, which claims benefit of Japanese Application No. 2004-301417 filedOct. 15, 2004. The entire disclosures of the prior applications arehereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a solution composition and polymerlight-emitting device (hereinafter, occasionally referred to polymerLED) using the same.

BACKGROUND ART

Various light-emitting devices using a polymer as a light-emittingmaterial (polymer LEDs) have been studied.

As a method for forming a light-emitting layer of a polymer LED, aforming method by an inkjet method using a solution compositioncontaining a polymer and a solvent has an advantage of enablingproduction of a light-emitting device of large area at low cost.

As solution compositions applicable to such inkjet method, for example,a solution composition containing a polyfluorene derivative and asolvent (WO00/59267 pamphlet) and a solution composition containingpolyarylenevinylenes and a solvent (WO02/96970 pamphlet, Kokai (Japanunexamined, patent publication) No. 2000-323276) are known.

However, when forming a light-emitting layer by an inkjet method using asolution composition, if the viscosity of the solution composition istoo low, this causes a problem that a film having high uniformity ishardly obtainable. Therefore, a solution composition having highviscosity is desired.

Furthermore, according to restrictions other than the viscosity, thesolution composition is required for keeping the polymer concentrationthereof within a specific range and having high viscosity; to meet thisrequirement, the conventional solution compositions are responding byselecting the kind of the solvent depending on the kind of the polymer.

DISCLOSURE OF THE INVENTION

After having diligently studied to solve the problems mentioned above,the present inventors have found that a solution composition employing apolymer having Z-average molecular weight in a specific range is highlyviscous, thus have achieved the present invention.

Namely, the invention provides a solution composition comprising one ormore solvent (s) and one or more polymer(s) having a polystyrene-reducedZ-average molecular weight of 1.0×10⁵ to 5.0×10⁶.

BEST MODE FOR CARRYING OUT THE INVENTION

The polymer used for the solution composition of the invention has apolystyrene-reduced Z-average molecular weight of 1.0×10⁵ to 5.0×10⁶,preferably 3.0×10⁵ to 3.0×10⁶, and more preferably 5.0×10⁵ to 1.5×10⁶.If the Z-average molecular weight of the polymer is too low, theviscosity thereof decreases and problems such as deteriorating theproperties of a device tends to be caused when the polymer is applied toa polymer LED; if the Z-average molecular weight thereof is too high,problems such as decrease of solubility in a solvent tends to be caused.

A number-average molecular weight is preferably 5.0×10⁴ to 3.0×10⁵, morepreferably 7.0×10⁴ to 2.5×10⁵, and even more preferably 1.0×10⁵ to2.0×10⁵.

A weight-average molecular weight is preferably 1.0×10⁵ to 1.0×10⁶, morepreferably 2.0×10⁵ to 7.0×10⁵, and even more preferably 3.0×10⁵ to5.0×10⁵.

Since the number-average molecular weight, weight-average molecularweight, and Z-average molecular weight are preferably in specific rangesrespectively, more preferable is a polymer having a polystyrene-reducednumber-average molecular weight of 5.0×10⁴ to 3.0×10⁵,polystyrene-reduced weight-average molecular weight of 1.0×10⁵ to1.0×10⁶, and polystyrene-reduced Z-average molecular weight of 3.0×10⁵to 3.0×10⁶.

The definitions of the Z-average molecular weight, number-averagemolecular weight, and weight-average molecular weight are disclosed inmany books, for example, being disclosed in (KAGAKU-DAIJITEN compactedition Vol. 8, page 224 (published by KYORITSU SHUPPAN CO., LTD.)).

The solution composition of the invention preferably has a viscosity of5 mPa·s or more and 20 mPa·s or less.

The polymer used for the solution composition of the invention is notparticularly limited as long as having the polystyrene-reduced Z-averagemolecular weight of 1.0×10⁵ to 5.0×10⁶; and a solution composition isstrongly desired for producing polymer LEDs, organic semiconductors, andorganic solar cells, and production thereof with using the solutioncomposition is advantageous to save industrial costs. Accordingly,polymers emitting fluorescence in the solid state, polymers emittingphosphorescence in the solid state, hole transporting polymers, electrontransporting polymers, and conductive polymers are exemplified as thepreferred examples, and polymers emitting fluorescence in the solidstate are exemplified as more preferred examples.

The polymer emitting fluorescence in the solid state includes aconjugated aromatic polymer which may be a homopolymer or a copolymer.In view of the properties of polymer LEDs, in a main chain of thepolymer, a carbon atom residing on an aromatic ring and other carbonatom residing on other aromatic ring of the adjacent repeating unit arepreferably bonded each other directly or through an oxygen atom,nitrogen atom, sulfur atom, or phosphor atom.

The conjugated aromatic polymer includes polymers having, as a repeatingunit, the following respective formulas (1-1), (1-2), (2), (2-2), (3),(4), (5-1), (5-2), (5-3), (5-4), arylene group, fluorenediyl group,divalent aromatic amine group, or divalent heterocyclic group.

In the formulas, A ring, B ring, C ring, D ring, E ring, and F ring eachindependently represent an aromatic ring. R represents an alkyl group,alkoxy group, alkylthio group, alkylsilyl group, alkyl amino group,hydroxyl group, amino group, carboxyl group, aldehyde group, cyanogroup, aryl group, aryloxy group, arylthio group, or arylalkyl group. Xrepresents —O—, —N(R)—, —Si(R)₂, —Se—, —B(R)—, —S—, —S(═O)—, —SO₂—,—P(═O)(R)— or —P(R)—. Y₁ and Y₂ each independently represent —O—, —S—,—C(R′)₂—, —C(═O)—, —S(═O)—, —SO₂—, —Si(R′)₂—, —N(R′)—, —B(R′)—, —P(R′)—,or —P(═O)(R′)—. R′ represents a hydrogen atom, alkyl group, alkoxygroup, alkylthio group, alkylsilyl group, alkylamino group, hydroxylgroup, amino group, carboxyl group, aldehyde group, cyano group, arylgroup, aryloxy group, arylthio group, and arylalkyl group. Wherein Y₁and Y₂ never become same each other. Z represents —C(R′)— or —N—. Arrepresents arylene group or divalent heterocyclic group. When aplurality of Rs, R′s, Xs, Zs, and Ars are contained in one structure,they may be the same or different each other. c1 and c2 eachindependently represent an integer of 0 or 1, and c3 each independentlyrepresents an integer of 0 to 2. d1 and d2 each independently representan integer of 0 to 4. e1 represents an integer of 0 to 5, and e2represents an integer of 0 to 3. f1 represents an integer of 0 to 5, andf2 represents an integer of 0 to 3. g1 represents an integer of 0 to 5,and g2 represents an integer of 0 to 3. h1 represents an integer of 0 to5, and h2 represents an integer of 0 to 3.

The repeating units mentioned above, in view of easiness of synthesis,solubility in a solvent, and the like, preferable are the above formulas(1-1), (2), (3), (4), (5-1), (5-2), (5-3), (5-4), and divalent aromaticamine group, arylene group, and fluorenediyl group; and more preferableare fluorenediyl group, divalent aromatic amine group, the aboveformulas (1-1), (5-1), (5-3), and (5-4).

The alkyl group may be a linear, branched, or cyclic chain, usually hasa carbon number of about 1 to 20, and examples thereof include methylgroup, ethyl group, propyl group, i-propyl group, butyl group, i-butylgroup, t-butyl group, pentyl group, isoamyl group, hexyl group,cyclohexyl group, heptyl group, octyl group, 2-ethylhexyl group, nonylgroup, decyl group, 3,7-dimethyloctyl group, and lauryl group.

The alkoxy group may be a linear, branched, or cyclic chain, usually hasa carbon number of about 1 to 20, and examples thereof include a methoxygroup, ethoxy group, propyloxy group, i-propyloxy group, butoxy group,i-butoxy group, t-butoxy group, pentyloxy group, iso-amyloxy group,hexyloxy group, cyclohexyloxy group, heptyloxy group, octyloxy group,2-ethylhexyloxy group, nonyloxy group, decyloxy group,3,7-dimethyloctyloxy group, and lauryloxy group.

The alkylthio may be a linear, branched, or cyclic chain, usually has acarbon number of about 1 to 20, and examples thereof include amethylthio group, ethylthio group, propylthio group, i-propylthio group,butylthio group, i-butylthio group, t-butylthio group, pentylthio group,hexylthio group, cyclohexylthio group, heptylthio group, octylthiogroup, 2-ethylhexylthio group, nonylthio group, decylthio group,3,7-dimethyloctylthio group, and laurylthio group.

The alkylsilyl group may be a linear, branched, or cyclic chain, usuallyhas a carbon number of about 1 to 60, and examples thereof include amethylsilyl group, ethylsilyl group, propylsilyl group, i-propylsilylgroup, butylsilyl group, i-butylsilyl group, t-butylsilyl group,pentylsilyl group, hexylsilyl group, cyclohexylsilyl group, heptylsilylgroup, octylsilyl group, 2-ethylhexylsilyl group, nonylsilyl group,decylsilyl group, 3,7-dimethyloctylsilyl group, laurylsilyl group,trimethylsilyl group, ethyldimethylsilyl group, propyldimethylsilylgroup, i-propyldimethylsilyl group, butyldimethylsilyl group,t-butyldimethylsilyl group, pentyldimethylsilyl group,hexyldimethylsilyl group, heptyldimethylsilyl group, octyldimethylsilylgroup, 2-ethylhexyl-dimethylsilyl group, nonyldimethylsilyl group,decyldimethylsilyl group, 3,7-dimethyloctyl-dimethylsilyl group, andlauryldimethylsilyl group.

The alkylamino group may be a linear, branched, or cyclic chain, and maybe monoalkylamino group or dialkylamino group, usually has a carbonnumber of about 1 to 40, and examples thereof include a methylaminogroup, dimethylamino group, ethylamino group, diethylamino group,propylamino group, i-propylamino group, butylamino group, i-butylaminogroup, t-butylamino group, pentylamino group, hexylamino group,cyclohexyl amino group, heptylamino group, octylamino group,2-ethylhexylamino group, nonylamino group, decylamino group,3,7-dimethyloctylamino group, and laurylamino group.

The aryl group typically has a carbon number of about 6 to 60, andexamples thereof include a phenyl group, naphthyl group, and anthracenylgroup.

The phenyl group of the aryl group includes a monovalent residue inwhich any one of R′s of a substituted or unsubstituted benzene of thefollowing structure is removed. As R′ in the following structure isexemplified with the concrete examples of the above R′ are exemplified.

The naphthyl group includes a monovalent residue in which any one of R′sof a substituted or unsubstituted naphthalene of the following structureis removed. As R′ in the following structure, the concrete examples ofthe above R′ are exemplified.

The anthracenyl group includes a monovalent residue in which any one ofR′s of a substituted or unsubstituted anthracene of the followingstructure is removed. As R′ in the following structure, the concreteexamples of the above R′ are exemplified.

The aryloxy group usually has a carbon number of about 6 to 60, andpreferably 7 to 48; concrete examples thereof include phenoxy group,C₁-C₁₂ alkoxyphenoxy group, C₁-C₁₂ alkylphenoxy group, and 1-naphthyloxygroup, 2-naphthyloxy group, pentafluorophenyloxy group, and preferablyC₁-C₁₂ alkoxyphenoxy group and C₁-C₁₂ alkylphenoxy group.

Concrete examples of C₁-C₁₂ alkoxy include methoxy, ethoxy, propyloxy,i-propyloxy, butoxy, i-butoxy, t-butoxy, pentyloxy, hexyloxy,cyclohexyloxy, heptyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, decyloxy,3,7-dimethyloctyloxy, and lauryloxy.

Concrete examples of C₁-C₁₂ alkylphenoxy group include methylphenoxygroup, ethylphenoxy group, dimethylphenoxy group, propylphenoxy group,1,3,5-trimethylphenoxy group, methylethylphenoxy group, i-propylphenoxygroup, butylphenoxy group, i-butylphenoxy group, t-butylphenoxy group,pentylphenoxy group, iso-amylphenoxy group, hexylphenoxy group,heptylphenoxy group, octylphenoxy group, nonylphenoxy group,decylphenoxy group, and dodecylphenoxy group.

The arylthio group usually has a carbon number of about 6 to 60, andpreferably 7 to 48; concrete examples thereof include phenylthio group,C₁-C₁₂ alkoxyphenylthio group, C₁-C₁₂ alkylphenylthio group,1-naphthylthio group, 2-naphthylthio group, and pentafluorophenylthiogroup, and preferably C₁-C₁₂ alkoxyphenylthio group and C₁-C₁₂alkylphenylthio group.

The arylalkyl group usually has a carbon number of about 7 to 60, andpreferably 7 to 48; concrete examples thereof include phenyl-C₁-C₁₂alkyl group, C₁-C₁₂ alkoxyphenyl-C₁-C₁₂ alkyl group, C₁-C₁₂alkylphenyl-C₁-C₁₂ alkyl group, 1-naphthyl-C₁-C₁₂ alkyl group, and2-naphthyl-C₁-C₁₂ alkyl group, and preferably C₁-C₁₂ alkoxyphenyl-C₁-C₁₂alkyl group and C₁-C₁₂ alkylphenyl-C₁-C₁₂ alkyl group.

As the above formula (1-1), the following structures are preferable.

As R in the above formula, the Rs mentioned above are exemplified, andalkyl group, alkoxy group, aryl group, and aryloxy group are preferable.

Specific examples of the above formula (1-1) include the followingstructures:

The above formula (1-2) preferably has the following structures:

The R in the above formula is exemplified with the R mentioned above,and preferably alkyl group, alkoxy group, aryl group, and aryloxy group.

Specific examples of the above formula (1-2) include the followingstructures:

The above formula (2) preferably has the following structures:

The R′ in the above formula is exemplified with the R′ mentioned above,and preferably alkyl group, alkoxy group, aryl group, and aryloxy group.

Specific examples of the above formulas (2) and (2-2) include thefollowing structures:

The above formula (3) preferably has the following structures:

As R in the above formula, the Rs mentioned above are exemplified, andalkyl group, alkoxy group, aryl group, and aryloxy group are preferable.

Specific examples of the above formula (3) include the followingstructures:

The above formula (4) preferably has the following structures:

As R in the above formula, the Rs mentioned above are exemplified, andalkyl group, alkoxy group, aryl group, and aryloxy group are preferable.

Specific examples of the above formula (4) include the followingstructures:

Specific examples of the above formulas (5-1), (5-2), (5-3), and (5-4)include the following structures:

The arylene group usually has a carbon number of about 6 to 60, concreteexamples thereof include phenylene group, naphthylene group, andanthracenediyl group. As the phenylene group, divalent residues in whichtwo of Rs of the benzene mentioned above are removed are exemplified, asthe naphthylene group, divalent residues in which two of Rs of thenaphthalene mentioned above are removed are exemplified, and as theanthracenediyl group, divalent residues in which two of Rs of theanthracene mentioned above are removed are exemplified.

As the fluorenediyl group, a divalent residue in which two of Rs of thefollowing structure are eliminated are exemplified.

In the above formula, R′ is exemplified with the R′ mentioned above andtwo of R′s are bonding links; W represents a hydrogen atom, alkyl group,aryl group, or monovalent heterocyclic group, and a plurality of Ws maybe same or different each other.

Of the optionally substituted fluorenediyl group, the followingstructure is preferable:

In the above structure, R′ and W represent the same meanings mentionedabove.

The monovalent heterocyclic group means an atomic group in which onehydrogen atom is removed from a heterocyclic compound, and usually has acarbon number of about 4 to 60, and preferably 4 to 20. The carbonnumber of the monovalent heterocyclic group does not include a carbonnumber of a substituent. The heterocyclic compounds, herein, meanorganic compounds having a ring structure in which atoms constitutingthe ring include not only a carbon atom but also a hetero atom such asoxygen, sulfur, nitrogen, silicon, selenium, phosphor, and boron.

The monovalent heterocyclic group includes 5 membered heterocyclic groupcontaining a hetero atom, 6 membered heterocyclic group containing ahetero atom, and a condensed heterocyclic group having 5 or 6 memberedheterocyclic ring containing a hetero atom. The hetero atom includesnitrogen, oxygen, sulfur, silicon, selenium, phosphor, and boron, andpreferably nitrogen, oxygen, and sulfur. Of the 6 membered heterocyclicgroups containing a hetero atom, preferable is the one containingnitrogen as the hetero atom.

The 5 membered heterocyclic group containing a hetero atom, for example,includes the following groups:

The 6 membered heterocyclic group containing a hetero atom, for example,includes the following groups:

The condensed heterocyclic group having 5 or 6 membered heterocyclicgroup containing a hetero atom, for example, includes the followinggroups:

R′ in the above monovalent heterocyclic group is exemplified with the R′mentioned above.

The divalent heterocyclic group is exemplified with a group in whichanother one R′ is further removed from the above monovalent heterocyclicgroup.

The divalent aromatic amine group includes a structure represented bythe following formula (6):

In the above formula, Ar₁, Ar_(2, Ar) ₃, and Ar₄ each independentlyrepresent arylene group or divalent heterocyclic group. Ar₅, Ar₆, andAr₇ each independently represent aryl group or monovalent heterocyclicgroup. Ar₁, Ar₂, Ar₃, Ar₄, and Ar₅ may have a substituent u and v eachindependently represent an integer of 0 or 1, and satisfy 0=u+v=1.

The divalent aromatic amine group preferably has the followingstructures:

R in the above formulas is exemplified with the R mentioned above, andpreferably alkyl group, alkoxy group, aryl group, and aryloxy group.

Specific examples of the divalent aromatic amine group are representedby the following structures:

The polymer contained in the solution composition of the invention, aslong as not spoiling fluorescence properties and charge injectingproperties, may contain a repeating unit other than the above formulas(1-1), (1-2), (2), (2-2), (3), (4), (5-1), (5-2), (5-3), and (5-4), andarylene group, fluorenediyl group, divalent aromatic amine group, anddivalent heterocyclic group. Regarding the repeating unit other than theabove formulas (1-1), (1-2), (2), (2-2), (3), (4), (5-1), (5-2), (5-3),and (5-4), and arylene group, fluorenediyl group, divalent aromaticamine group, and divalent heterocyclic group, they are preferably 30% bymoles or less based on the sum of total repeating units, more preferably20% by moles or less, even more preferably 10% by moles or less, andstill particularly preferably being not contained substantially.

The solution composition of the invention satisfies the characteristicsdesired for coating by inkjet method, the characteristics being not onlythe viscosity thereof but also the properties that a polymerconcentration in the composition is 1% by weight or less, a film formedtherefrom has a high toughness, viscosity change thereof is small afterlong preservation, a nozzle of an inkjet printer is never clogged, and afilm formed from the composition emits light with strong intensity.

The polymer used for the solution composition of the invention can beproduced, for example, by reacting a monomer represented by the generalformulas (7), (8), and (9) and/or (10):

K₁—Ar₁₁—K₂  (7)

K₃—Ar₁₂—K₄  (8)

K₅-L₁  (9)

K₆-L₂  (10)

(wherein Ar₁₁ and Ar₁₁ each independently represent optionallysubstituted fluorenediyl group. L₁ and L₂ represent a terminal grouprespectively. K₁, K₂, K₃, K₄, K₅, and K₆ each independently represent aleaving group. L₁ and L₂ are different each other).

The polymer used for the solution composition of the invention, in orderto increase the molecular weight thereof, may be polymerized withcontaining a monomer represented by the formula (11) which has threeleaving groups:

K₁—Ar₁₁(—K₇)—K₂  (11)

(wherein Ar₁₁ represents the substituent mentioned above, and K₁, K₂,and K₇ each independently represent a leaving group).

The polymer is preferably a polymer produced by removing leaving groupsof a monomer having two leaving groups, 99.9 to 99.5% by mole, and amonomer having three leaving groups, 0.1 to 0.5% by mole.

In order to increase the molecular weight of a polymer used for asolution composition of the invention, other than the monomersrepresented by the formulas (7) to (11), a monomer having four leavinggroups may be included for the polymerization.

Examples of the leaving group include a halogen atom, alkylsulfonyloxygroup, arylsulfonyloxy group, or a group represented by —B(OR₁₁)₂(wherein R₁₁ is a hydrogen atom or alkyl group).

Examples of the halogen atom includes a chlorine atom, bromine atom, andiodine atom, preferably a chlorine atom and bromine atom, and morepreferably a bromine atom. The alkylsulfonyloxy group may be substitutedwith a fluorine atom, and examples thereof includetrifluoromethanesulfonyloxy group and the like. The arylsulfonyloxygroup may be substituted with alkyl group, and examples thereof includephenylsulfonyloxy group, trisulfonyloxy group, and the like.

In the group represented by —B(OR₁₁)₂, R₁₁ is a hydrogen atom or alkylgroup. The alkyl group usually has a carbon number of about 1 to 20, andexamples thereof include methyl group, ethyl group, propyl group, butylgroup, hexyl group, octyl group, dodecyl group, and the like. The alkylgroups may be connected each other to form a ring.

Concrete examples of the groups represented by —B(OR₁₁)₂ include thefollowings,

and preferably include the followings,

When the monomer represented by the general formula (11) is notcontained, the total supplied amount of the monomers represented by thegeneral formulas (9) and (10) is usually 0.1 to 10% by mole with respectto the total supplied amount of the monomers represented by the generalformulas (7) and (8), preferably 0.2 to 5% by mole, and more preferably0.5 to 3% by mole.

When the monomer represented by the general formula (11) is contained,this may cause problems that, if an amount of the monomer represented bythe general formula (11) is too small, the effect of increasing amolecular weight is small, and if being too large, the resultant polymerbecomes difficult to dissolve in widely-used solvents. The totalsupplied amount of the monomers represented by the general formulas (9)and (10) is typically 0.1 to 10% by mole with respect to the totalsupplied amount of the monomers represented by the general formulas (7),(8), and (11), preferably 0.2 to 5% by mole, and more preferably 0.5 to3% by mole. The supplied amount of the monomer represented by thegeneral formula (11) is preferably 0.05 to 1.0% by mole with respect tothe total supplied amount of the monomers represented by the generalformulas (7), (8), and (11), and more preferably 0.1 to 0.5% by mole.

As the method for producing the polymer used in the invention,exemplified are: a method of polymerization from the correspondingmonomers mentioned above by Suzuki's reaction (Chem. Rev., Vol.-95, page2457 (1995)), a method of polymerization by Grignard reaction (KYORITSUSHUPPAN CO., LTD. KOUBUNSI KINOUZAIRYOU SERIES Vol. 2, KOUBUNSI NOGOUSEI TO HANNOU(2), page 432-3), a method of polymerization byYamamoto's polymerization method (Prog. Polym. Sci., Vol. 17, page1153-1205, 1992), a method of polymerization by using an oxidizing agentsuch as FeCl₃, and electrochemical oxidative polymerization (MARUZENCO., LTD., JIKKEN KAGAKU KOUZA fourth edition, Vol. 28, page 339-340).

The case of using Suzuki's reaction is explained. In this case,employing monomers wherein K₁ and K₂ are each independently the grouprepresented by —B(OR₁₁)₂ (wherein R₁₁ is a hydrogen atom or alkylgroup), K₃ and K₄ are each independently a halogen atom,alkylsulfonyloxy group, or arylsulfonyloxy group, K₅ is the grouprepresented by —B(OR₁₁)₂ (wherein R₁₁ is a hydrogen atom or alkylgroup), and K₆ is a halogen atom, alkylsulfonyloxy group, orarylsulfonyloxy group; these monomers are reacted in the presence ofPd(0) catalyst to produce a polymer.

In this case, in a reaction requiring two or more monomers having twoleaving groups wherein at least one of the monomers is the monomerhaving two —B(OR₁₁)₂s (wherein R₁₁ is a hydrogen atom or alkyl group)and at least other one of the monomers is the monomer having two unitsselected from the group of a halogen atom, alkylsulfonyloxy group, andarylsulfonyloxy group, usually monomers represented by formulas (7) and(8) are reacted for about 1 to 100 hours, then monomer (9) is added inthe reaction system, and further reacted for about 0.5 to 50 hours, andthen monomer (10) is added in the reaction system to react for about 0.5to 50 hours.

The reaction is conducted, for example, with usingpalladium[tetrakis(triphenylphosphine)] or palladium acetate as a Pd(0)catalyst, and adding an inorganic base such as potassium carbonate,sodium carbonate, and barium hydroxide, organic base such astriethylamine, and inorganic salt such as cesium fluoride in an amountof equivalent or more per monomer, and preferably 1 to 10 equivalent.The reaction may be conducted in a two-phase system with using anaqueous solution of an inorganic salt. As the solvent to be used,exemplified are N,N-dimethylformamide, toluene, dimethoxyethane, andtetrahydrofuran. A reaction temperature is preferably about 50 to 160°C. depending on the solvent used. It may be heated near to the boilingpoint of the solvent and refluxed. The reaction time is about 1 hour to200 hours.

The case of using Yamamoto's polymerization is explained. In this case,for example, employing monomers wherein K₁, K₂, K₃, K₄, K₅, K₆, and K₇are each independently a halogen atom, alkylsulfonyloxy group, orarylsulfonyloxy group; these monomers are reacted in the presence ofNi(0)complex to produce a polymer. The reaction is usually conducted bymixing all of monomers (7) to (11).

One method is to use a Ni(0)complex (zero-valent nickel complex), and asthe nickel complex, a zero-valent nickel is used as itself, and anothermethod is to react a nickel salt in the presence of a reducing agent andgenerate a zero-valent nickel in situ. As the zero-valent nickelcomplex, bis(1,5-cyclooctadiene)nickel(0),(ethylene)bis(triphenylphosphine)nickel(0), andtetrakis(triphenylphosphine)nickel are exemplified, and among of thembis(1,5-cyclooctadiene)nickel(0) is preferable in view of versatilityand low cost. Furthermore, addition of a neutral ligand is preferable inview of enhancing a yield. The neutral -ligand means a ligand havingneither an anion nor a cation, examples thereof include nitrogencontaining ligands such as 2,2′-bipyridyl, 1,10-phenanthroline,methylenebisoxazoline, and N,N-tetramethylethylenediamine; and tertiaryphosphine ligands such as triphenylphosphine, tritolylphosphine,tributylphosphine, and triphenoxyphosphine; and nitrogen containingligands being preferable in view of versatility and low cost, and2,2′-bipyridyl being particularly preferable in view of high reactivityand high yield. In view of enhancing a yield of a polymer, particularlypreferable is a system in which the system containingbis(1,5-cyclooctadiene)nickel(0) is added with 2,2′-bipyridyl as aneutral ligand. In the method of reacting a zero-valent nickel in situ,as the nickel salt, nickel chloride and nickel acetate are exemplified.As the reducing agent, zinc, sodium hydride, hydrazine and derivativesthereof, lithium aluminum hydride, etc. are exemplified; and, ifrequired, as the additive, such as ammonium iodide, lithium iodide, andpotassium iodide may be used. A solvent for polymerization is notparticularly limited as long as not inhibiting the polymerization, andbeing preferably the one containing one or more kind(s) of aromatichydrocarbon solvent and/or ether solvent. Examples of the aromatichydrocarbon solvent include benzene, toluene, xylene, trimethylbenzene,tetramethylbenzene, butylbenzene, naphthalene, and tetralin; andpreferably being toluene, xylene, tetralin, and tetramethylbenzene.Examples of the ether solvent include diisopropyl ether,tetrahydrofuran, 1,4-dioxane, diphenyl ether, ethyleneglycoldimethylether, and tert-butylmethyl ether, and preferably tetrahydrofuran and1,4-dioxane which are a good solvent to polymer compounds. Among thesolvents, tetrahydrofuran is most preferable. Furthermore, in view ofimproving polymerization ability and solubility, the solvent, as long asnot inhibiting the polymerization, may use a solvent of the aromatichydrocarbon solvent and/or ether solvent mixed with a solvent other thanthe aromatic hydrocarbon solvent and ether solvent. Reaction proceduresand the like may be conducted, for example, according to a methoddisclosed in Kokai No. 2000-44544. In Yamamoto's polymerization, thepolymerization reaction, for example, is usually conducted under aninert gas atmosphere such as argon or nitrogen, in the solvent oftetrahydrofuran, at a temperature of 60° C., and in the presence of azero-valent nickel complex and neutral ligand. A polymerization time isusually about 0.5 to 100 hours, and preferably 10 hours or less in viewof production cost. The polymerization temperature is usually about 0 to200° C., and preferably 20 to 100° C. in view of high yield and savingheating cost.

When a neutral ligand is used, the amount is preferably about 0.5 to 10moles with respect to 1 mole of the zero-valent nickel complex in viewof reaction yield and cost, more preferably 0.8 to 1.5 moles, and evenmore preferably 0.9 to 1.1 moles.

The amount of zero-valent nickel complex to be used is not particularlylimited as long as not inhibiting the polymerization; if the amount istoo small, a resulting molecular weight tends to become smaller; ifbeing too large, after-treatments tend to become troublesome; therefore,the amount is preferably 0.1 to 10 moles with respect to 1 mole of amonomer, more preferably 1 to 5 moles, and even more preferably 2 to 3.5moles.

When the polymer is used as a light-emitting material of polymer LEDs,the polymerization is preferably conducted after purifying un-reactedmonomers with distillation, sublimation, re-crystallization, and thelike; moreover, after the polymerization, the polymer may be subjectedto purification treatment such as re-precipitation or fractionation withchromatography.

The polymer contained in the solution composition of the invention maybe one kind or 2 or more kinds thereof; in order to sharing variousfunctions such as transporting charge and light emission, preferablybeing 2 or more kinds of polymers. In view of cost, the polymercontained in the solution composition is preferably 2 to 3 kindsthereof, and more preferably 2 kinds.

When the solution composition of the invention contains 2 or more kindsof polymers, at least one of polymers must be the polymer emittingfluorescence in the solid state. When 2 kinds of polymers are contained,in view of characteristics of a device, the following cases arepreferable: containing a polymer having the above formula (1-1) as arepeating unit thereof and a polymer having divalent aromatic aminegroup as a repeating unit thereof; containing a polymer having the aboveformula (1-1) as a repeating unit thereof and a polymer having the aboveformula (5-1) as a repeating unit thereof; containing a polymer havingthe above formula (1-1) as a repeating unit thereof and a polymer havingthe above formula (5-2) as a repeating unit thereof; containing apolymer having the above formula (5-1) as a repeating unit thereof and apolymer having divalent aromatic amine group as a repeating unitthereof; containing a polymer having the above formula (5-2) as arepeating unit thereof and a polymer having divalent aromatic aminegroup as a repeating unit thereof; containing a polymer havingfluorenediyl group as a repeating unit thereof and a polymer havingdivalent aromatic amine group as a repeating unit thereof; andcontaining a polymer having the above formula (1-1) as a repeating unitthereof and a polymer having fluorenediyl group as a repeating unitthereof.

The solvent used for the solution composition of the invention isusually an organic solvent, and examples thereof include aromatichydrocarbon solvents, aliphatic hydrocarbon solvents, alcohol solvents,glycol solvents, ester solvents, aldehyde solvents, ketone solvents,carboxyl solvents, acetate solvents, ether solvents, nitrogen containingsolvents, and sulfur containing solvents.

Examples of the aromatic hydrocarbon solvents include benzene,alkylbenzenes, naphthalene, alkylnaphthalenes, anthracene, phenanthrene,and the like. The alkylbenzenes are exemplified with toluene, o-xylene,p-xylene, m-xylene, mesitylene, 1,2,4-trimethylbenzene,tetramethylbenzene, ethylbenzene, n-propylbenzene, i-propylbenzene,n-butylbenzene, s-butylbenzene, i-butylbenzene, t-butylbenzene,n-pentylbenzene, n-hexylbenzene, n-heptylbenzene, n-octylbenzene,n-nonylbenzene, n-decylbenzene, o-diethylbenzene, m-diethylbenzene,p-diethylbenzene, 1,2,4-triethylbenzene, 1,3,5-triethylbenzene,tetraethylbenzene, o-ethylmethylbenzene, p-ethylmethylbenzene,m-ethylmethylbenzene, di-n-propylbenzene, di-1-propylbenzene,tri-n-propylbenzene, ethyl-n-propylbenzene, ethyl-1-propylbenzene,ethyl-n-propylbenzene, methyl-1-propylbenzene, methyl-n-propylbenzene,cyclohexylbenzene, tetralin, methyltetralin, styrene, biphenyl, indene,and fluorene. The alkylnaphthalenes are exemplified witha-methylnaphthalene, β-methylnaphthalene, a-ethylnaphthalene,β-ethylnaphthalene, n-propylnaphthalene, and 1,4-dimethylnaphtalene.

Examples of the aliphatic hydrocarbon solvents include n-pentane,isopentane, n-hexane, isohexane, n-heptane, isoheptane, n-octane,isooctane, nonane, n-decan, n-undecane, n-dodecane, isododecane,n-tridecane, n-tetradecane, cyclopentane, cyclopentene, cyclohexane,methylcyclohexane, dimethylcyclohexane, ethylcyclohexane, cyclohexene,cycloheptane, decalin, and norbornane.

Examples of the alcohol solvents include aliphatic alcohol solvents andaromatic alcohol solvents. The aliphatic alcohol solvents areexemplified with methanol, ethanol, 1-propanol, n-propanol, i-butanol,n-butanol, t-butanol, s-butanol, 3-methoxy-1-butanol, n-pentanol,3-methyl-1-butanol, n-hexanol, n-heptanol, n-octanol,2-ethyl-1,3-hexyldiol, 2-ethyl-1-hexanol, n-nonylalcohol, n-decanol,isodecylalcohol, isotridecylalcohol, 4-hydroxy-4-methyl-2-pentanone,methylisobutylcarbinol, cyclopentanol, cyclohexanol, methylcyclohexanol,cyclohexenol, cyclohexylmethanol, tetrahydrofurfurylalcohol, andfurfuryl alcohol. The aromatic alcohol solvents are exemplified withphenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol,p-ethylphenol, 2,3-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol,4-methoxyphenol, o-t-butylphenol, p-t-butylphenol, 2,4-di-t-butylphenol,2,6-di-t-butylphenol, 2-methyl-6-t-butylphenol, o-phenylphenol,m-phenylphenol, p-phenylphenol, a-naphthol, β-naphthol, andbenzylalcohol.

Examples of the glycol solvents include ethylene glycol, diethyleneglycol, triethylene glycol, ethyleneglycol dimethyl ether,ethyleneglycol mono-butylether, ethyleneglycol mono-t-butylether,propylene glycol, isoprene glycol, dipropylene glycol, tripropyleneglycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol,1,5-pentanediol, 1,6-hexanediol, 2-methyl-2,4-pentanediol, and3-methyl-1,5-pentanediol.

Examples of the ester solvents include aliphatic ester solvents andaromatic ester solvents. The aliphatic ester solvents are exemplifiedwith methyl formate, ethyl formate, n-butyl formate, n-propyl formate,methyl acetate, ethyl acetate, allyl acetate, isopropyl acetate, n-butylacetate, n-propyl acetate, diethyl succinate, dimethyl succinate,dimethyl carbonate, propylene carbonate, diethyl oxalate, dimethyloxalate, methyl lactate, ethyl lactate, butyl lactate, methyl pyruvate,ethyl pyruvate, dimethyl malonate, diethyl malonate, andγ-butyrolactone. The aromatic ester solvents are exemplified withdiallyl isophthalate, dimethyl isophthalate, diethyl isophthalate,dimethyl terephthalate, diethyl terephthalate, methyl benzoate, ethylbenzoate, n-propyl benzoate, and n-butyl benzoate.

Examples of the aldehyde solvents include aliphatic aldehyde solventsand aromatic aldehyde solvents. The aliphatic aldehyde solvents areexemplified with acetaldehyde, propione aldehyde, and furfural. Thearomatic aldehyde solvents are exemplified with benzaldehyde.

Examples of the ketone solvents include aliphatic ketone solvents andaromatic ketone solvents. The aliphatic ketone solvents are exemplifiedwith acetone, methylethyl ketone, methylisopropyl ketone, methyisobutylketone, diisopropyl ketone, diisobutyl ketone, cyclopentanone,cyclohexanone, 2-(1-cyclohexenyl)cyclohexanone, methylcyclohexanone, and4-hydroxy-2-butanone. The aromatic ketone solvents are exemplified withpropiophenone and benzophenone.

Examples of the carboxyl solvents include aliphatic carboxyl solventsand aromatic carboxyl solvents. The aliphatic carboxyl solvents areexemplified with formic acid, oxalic acid, propionic acid, anddodecanedioic acid. The aromatic carboxyl solvents are exemplified withbenzoic acid, isophthalic acid, o-toluic acid, m-toluic acid, p-toluicacid, a-naphthoic acid, β-naphthoic acid, phenylacetic acid, andphenoxyacetic acid.

Examples of the acetate solvents include aliphatic acetate solvents andaromatic acetate solvents. The aliphatic acetate solvents areexemplified with propyleneglycolmonomethylether acetate, 3-methoxybutylacetate, and 3-methoxy-3-methylbutyl acetate.

Examples of the ether solvents include aliphatic ether solvents andaromatic ether solvents. The aliphatic ether solvents are exemplifiedwith methyl-t-butyl ether, diethyl ether, propyl ether, isopropyl ether,dibutyl ether, diisoamyl ether, 2,2-dimethoxy propane,propyleneglycolmonomethyl ether, dioxane, 1,3-dioxolane,cyclohexeneoxide, 2,3-dihydropyrane, tetrahydrofuran, andtetrahydropyrane. The aliphatic ether solvents are exemplified withanisole, ethoxyphenol, o-dimethoxybenzene, p-dimethoxybenzene, andbenzyl ether.

Examples of the nitrogen containing solvents include aliphatic nitrogencontaining solvents and aromatic nitrogen containing solvents. Thealiphatic nitrogen containing solvents are exemplified withacetonitrile, amyl acetate, acetic acid amide, N,N-diisopropylethylamine, cyclohexylamine, N,N-dimethylacetamide, N,N-dimethylformamide,and imidazole. The aromatic nitrogen containing solvents are exemplifiedwith o-anisidine, p-anisidine, m-anisidine, aniline, p-aminoacetanilide,o-aminophenol, m-aminophenol-, p-aminophenol, o-toluidine, m-toluidine,p-toluidine, N-methylaniline, N,N-dimethylaniline, N-ethylaniline,N,N-diethylaniline, diphenylamine, N,N-dimethyl-p-toluidine, pyridine,and quinoline.

Examples of the sulfur containing solvents include aliphatic sulfurcontaining solvents and aromatic sulfur containing solvents. Thealiphatic sulfur containing solvents are exemplified with dimethylsulfoxide and thiodiglycol. The aromatic sulfur containing solvents areexemplified with diphenylsulfide, diphenylsulfone, and benzylmercaptan.

The solvent is preferably aliphatic hydrocarbon solvents, aromatichydrocarbon solvents, alcohol solvents, ether solvents, ester solvents,and ketone solvents; and more preferably aliphatic hydrocarbon solvents,aromatic hydrocarbon solvents, aromatic ether solvents, and aromaticester solvents.

The solution composition of the invention is characterized by dissolvinga polymer in one or more kind(s) of solvent(s); and preferably dissolvedin 2 or more kinds of solvents. The kind of solvents is not particularlylimited; preferably including one or more kind(s) of solvent(s) whichhas favorable solubility for a polymer and other one or more kind(s) ofsolvent(s) which rapidly increases the viscosity during drying thesolvent for securing the uniformity of a film. Furthermore, regardingeasiness of preparing a solution composition, 2 to 5 kinds of solventsare preferably used, and more preferably 2 to 3 kinds.

When the solution composition of the invention contains 2 or more kindsof solvents, the mixture of the solvents may include a solvent beingsolid at 25° C., but the mixture itself must be liquid at 25° C.

When the solution composition of the invention applies 2 or more kindsof solvents, in view of uniformity of a film to be formed, at least onekind of the solvents preferably has a boiling point of 180° C. or more,more preferably 180 to 250° C., and even more preferably 200 to 250° C.

Among the above solvents, in view of solubility and film-formingproperty, the followings are preferable: combination of one kind ofaliphatic hydrocarbon solvent and one kind of aromatic hydrocarbonsolvent; combination of one kind of aliphatic hydrocarbon solvent andone kind of aromatic ether solvent; combination of one kind of aliphatichydrocarbon solvent and one kind of aromatic ester solvent; combinationof two kinds of aromatic hydrocarbon solvents; combination of two kindsof aliphatic hydrocarbon solvents and one kind of aromatic hydrocarbonsolvent; combination of one kind of aliphatic hydrocarbon solvent andtwo kinds of aromatic hydrocarbon solvents; combination of one kind ofaliphatic hydrocarbon solvent and one kind of aromatic ether solvent;combination of two kinds of aliphatic hydrocarbon solvents and one kindof aromatic ether solvent; combination of one kind of aliphatichydrocarbon solvent, one kind of aromatic hydrocarbon solvent, and onekind of aromatic ether solvent; and combination of one kind of aliphatichydrocarbon solvent, one kind of aromatic hydrocarbon solvent, and onekind of aromatic ester solvent; and more preferably combination of onekind of aliphatic hydrocarbon solvent and one kind of aromatichydrocarbon solvent; combination of one kind of aliphatic hydrocarbonsolvent and one kind of aromatic ether solvent; and combination of onekind of aliphatic hydrocarbon solvent and one kind of aromatic estersolvent.

When combination of two kinds or more solvents are used, in order toreduce a flowability of a film while drying the solvents, a content ofthe solvent having the highest solubility to a polymer is preferably 10%by weight or more and 50% by weight or less with respect to the totalamount of the solvents, and more preferably 10% by weight or more and30% by weight or less. For example, when a solution composition isprepared from an aromatic polymer, anisole, and bicyclohexyl, the weightof anisole is preferably 50% by weight or less with respect to the totalweight of anisole and bicyclohexyl, and more preferably 30% by weight orless.

As viscometers, capillary viscometers, rotating viscometers, andfalling-ball viscometers are known; for determining a viscosity in theinvention, a cone-plate type rotating viscometer is employed because itcan easily determine a viscosity of a solution composition with smallamount. Specifically, the measurement is conducted with usingLVDV-II+Pro manufactured by BROOKFIELD.

The concentration of the polymer contained in the solution compositionof the invention is preferably 0.5 to 2.0% by weight, and morepreferably 0.7 to 1.2% by weight. If the concentration is too low, thistends to require plurally coating the solution composition to obtain anintended film thickness; on the other hand, if being too high, thistends to cause a thicker film.

A film formed with using the solution composition of the invention canhave a high toughness. Various ways are possible to determine thetoughness; as a simple way, toughness can be determined by comparing thetime that a film formed on a substrate is exposed with an ultrasonicwave until removing from the substrate.

Regarding the storage stability of the solution composition of theinvention, it is preferable that the viscosity change at 30 days passingafter preparing the solution composition is within ±5% with respect tothe viscosity thereof at the time of the preparation, and morepreferable that the viscosity change at 90 days passing after preparingthe solution composition is within ±5% with respect to the viscositythereof at the time of the preparation.

A thin film formed with using the solution composition of the inventioncan be applied to various applications. Methods for forming a thin filmcan employ coating methods such as spin coat methods, casting methods,micro gravure coat methods, gravure coat methods, bar coat methods, rollcoat methods, wire-bar coat methods, dip coat methods, spray coatmethods, screen printing methods, flexographic printing methods, offsetprint methods, and inkjet methods.

An optimal film thickness of the thin film varies depending on thematerials used or intended uses thereof; for example, being 1 nm to 1μm, preferably 2 nm to 500 nm, and more preferably 5 nm to 200 nm.

Applications of the thin film include polymer LEDs, organic transistors,organic solar cells, conductive thin films, secondary batteries,coloring matters for lasers, electrophotography photoconductors,photosensitive films, organic capacitors, color filters, organicsuperconductors, electromagnetic wave shields, and polymerpiezo-electric substances.

The polymer LED of the invention is characterized by having alight-emitting layer between electrodes composed of a anode and acathode, wherein the light-emitting layer is formed with using thesolution composition of the invention. The polymer LED of the inventionalso includes a polymer light-emitting device having a layer including aconductive polymer which is disposed between at least one electrode andthe light-emitting layer, and being adjacent to the electrode; and apolymer light-emitting device having an insulating layer having averagefilm thickness of not more than 2 nm which is disposed between at leastone electrode and the light-emitting layer, and being adjacent to theelectrode.

Furthermore, the polymer LED of the invention includes a polymer LEDhaving an electron transporting layer between the cathode andlight-emitting layer, a polymer LED having a hole transporting layerbetween the anode and light-emitting layer, a polymer LED having anelectron transporting layer between the cathode and light-emitting layeras well as a hole transporting layer between the anode andlight-emitting layer, and the like.

As the structures of the polymer LED of the invention, the followingstructures of a) to d) are specifically exemplified:

a) anode/light-emitting layer/cathode,b) anode/hole transporting layer/light-emitting layer/cathode,c) anode/light-emitting layer/electron transporting layer/cathode, andd) anode/hole transporting layer/light-emitting layer/electrontransporting layer/cathode(wherein the mark “/” denotes that respective layers are layeredadjacent each other; hereinafter, denoting the same).

Herein, the light-emitting layer represents a layer having a function ofemitting light, the hole transporting layer represents a layer having afunction of transporting a hole, and the electron transporting layerrepresents a layer having a function of transporting an electron. Forconvenience, the electron transporting layer and hole transporting layerare collectively dubbed as a charge transporting layer. Thelight-emitting layer, hole transporting layer, and electron transportinglayer may each independently apply 2 or more layers thereof.

Of a charge transporting layer disposed adjacent to an electrode, theone having a function of improving an efficiency of injecting chargefrom the electrode and an effect of lowering a voltage driving of adevice is particularly dubbed as a charge injection layer (holeinjection layer, electron injection layer).

Furthermore, in order to enhance adhesibility with an electrode andimprove charge injection from an electrode, the charge injection layermentioned above or an insulating layer having a film thickness of 2 nmor less may be disposed adjacent to the electrode; and in order toenhance adhesibility of an interface and prevent a mixing, a thininsulating layer may be inserted in the interface of the chargeinjection layer or light-emitting layer. The order and number of thelayers to be layered, and the thickness of the respective layers may beappropriately set with considering a light-emitting efficiency anddevice life.

In the invention, the polymer LED having a charge injection layer(electron injection layer, hole injection layer) includes a polymer LEDhaving a charge injection layer adjacent to the cathode, and a polymerLED having a charge injection layer adjacent to the anode. For example,the following structures of e) to p) are included specifically:

e) anode/charge injection layer/light-emitting layer/cathode,f) anode/light-emitting layer/charge injection layer/cathode,g) anode/charge injection layer/light-emitting layer/charge injectionlayer/cathode,h) anode/charge injection layer/hole transporting layer/light-emittinglayer/cathode,i) anode/hole transporting layer/light-emitting layer/charge injectionlayer/cathode,j) anode/charge injection layer/hole transporting layer/light-emittinglayer/charge injection layer/cathode,k) anode/charge injection layer/light-emitting layer/electrontransporting layer/cathode,l) anode/light-emitting layer/electron transporting layer/chargeinjection layer/cathode,m) anode/charge injection layer/light-emitting layer/electrontransporting layer/charge injection layer/cathode,n) anode/charge injection layer/hole transporting layer/light-emittinglayer/electron transporting layer/cathode,o) anode/hole transporting layer/light-emitting layer/electrontransporting layer/charge injection layer/cathode, andp) anode/charge injection layer/hole transporting layer/light-emittinglayer/electron transporting layer/charge injection layer/cathode.

Specific examples of the charge injection layer include a layer having aconductive polymer; a layer disposed between the anode and holetransporting layer, having a material of which ionization potentialvalue belongs between that of a anode material and that of a holetransporting material contained in the hole transporting layer; and alayer disposed between the cathode and electron transporting layer,having a material of which electronic affinity belongs between that of acathode material and that of an electron transporting material containedin the electron transporting layer.

When the charge injection layer mentioned above is a layer containing aconductive polymer, the electric conductivity of the conductive polymeris preferably 10⁻⁵ S/cm or more and 10³ or less; and, in order to reducea leakage current between light-emitting pixels, preferably 10⁻⁵ S/cm ormore and 10² or less, and more preferably 10⁻⁵ S/cm or more and 10¹ orless.

When the charge injection layer mentioned above is a layer containing aconductive polymer, the electric conductivity of the conductive polymeris preferably 10⁻⁵ S/cm or more and 10³ S/cm or less; and, in order toreduce a leakage current between light-emitting pixels, preferably 10⁻⁵S/cm or more and 10² S/cm or less, and more preferably 10⁻⁵ S/cm or moreand 10¹ S/cm or less. The conductive polymer is usually doped with anappropriate amount of ion to render the electric conductivity of theconductive polymer 10⁻⁵ S/cm or more and 10³ or less.

A kind of ion to be doped is anion for the hole injection layer, orcation for the electron injection layer. The anion is exemplified withpolystyrenesulfonate ion, alkylbenzenesulfonic acid ion, and camphorsulfonic acid ion; and the cation is exemplified with lithium ion,sodium ion, potassium ion, and tetrabutylammonium ion. A film thicknessof the charge injection layer, for example, is 1 nm to 100 nm, andpreferably 2 nm to 50 nm.

The material used for the charge injection layer may be appropriatelyselected with considering materials applied to the electrode or anadjacent layer, and examples thereof include polyaniline and itsderivatives, polythiophene and its derivatives, polypyrrole and itsderivatives, polyphenylenevinylene and its derivatives,polythienylenevinylene and its derivatives, polyquinoline and itsderivatives, polyquinoxaline and its derivatives, conductive polymerssuch as polymers having an aromatic amine structure in their main chainor side chain, metal phthalocyanine (copper phthalocyanine etc.), andcarbon.

The insulating layer having a film thickness of 2 nm or less has afunction to make charge injection easy. A material for the insulatinglayer mentioned above includes metal fluorides, metal oxides, andorganic insulating materials. The polymer LED having the insulatinglayer with a film thickness of 2 nm or less includes a polymer LEDdisposing the insulating layer with a film thickness of 2 nm or lessadjacent to the cathode, and a polymer LED disposing the insulatinglayer with a film thickness of 2 nm or less adjacent to the anode.

Specifically the following structures of q) to ab) are exemplified:

q) anode/insulating layer with a film thickness of 2 nm orless/light-emitting layer/cathode,r) anode/light-emitting layer/insulating layer with a film thickness of2 nm or less/cathode,s) anode/insulating layer with a film thickness of 2 nm orless/light-emitting layer/insulating layer with a film thickness of 2 nmor less/cathode,t) anode/insulating layer with a film thickness of 2 nm or less/holetransporting layer/light-emitting layer/cathode,u) anode/hole transporting layer/light-emitting layer/insulating layerwith a film thickness of 2 nm or less/cathode,v) anode/insulating layer with a film thickness of 2 nm or less/holetransporting layer/light-emitting layer/insulating layer with a filmthickness of 2 nm or less/cathode,w) anode/insulating layer with a film thickness of 2 nm orless/light-emitting layer/electron transporting layer/cathode,x) anode/light-emitting layer/electron transporting layer/insulatinglayer with a film thickness of 2 nm or less/cathode,y) anode/insulating layer with a film thickness of 2 nm orless/light-emitting layer/electron transporting layer/insulating layerwith a film thickness of 2 nm or less/cathode,z) anode/insulating layer with a film thickness of 2 nm or less/holetransporting layer/light-emitting layer/electron transportinglayer/cathode,aa) anode/hole transporting layer/light-emitting layer/electrontransporting layer/insulating layer with a film thickness of 2 nm orless/cathode, andab) anode/insulating layer with a film thickness of 2 nm or less/holetransporting layer/light-emitting layer/electron transportinglayer/insulating layer with a film thickness of 2 nm or less/cathode.

Methods for forming a film of a light-emitting layer applying thesolution composition of the invention can employ coating methodsincluding spin coat methods, casting methods, micro gravure coatmethods, gravure coat methods, bar coat methods, roll coat methods,wire-bar coat methods, dip coat methods, spray coat methods, screenprinting methods, flexographic printing methods, offset print methods,and inkjet methods. Among of them, inkjet methods are preferably used.

The inkjet method is a method of spitting out a polymer solution with aninkjet device and the like after the polymer solution is prepared bydissolving a polymer in a solvent. An additive and dopant may becontained in the polymer solution in its preparation. This method isadvantageous for selective coloring and for effectively utilizing amaterial with minimizing the loss thereof.

However, coating with the inkjet method may cause a problems: if apolymer concentration of the solution composition is too high, athickness of the thin film obtained by coating becomes thick; and if apolymer concentration of the solution composition is too low, thisrequires plurally coating to obtain an intended film thickness, andresulting in increase of production cost. To avoid these problems, thepolymer concentration of the solution composition is preferablycontained in the range of 0.5 to 1.5% by weight, and more preferably 0.7to 1.2% by weight.

An optimal film thickness of the light-emitting layer varies dependingon the materials applied and may be set at the thickness of makingvalues of a driving voltage and light emission efficiency reasonable,for example, being 1 nm to 1 μm, preferably 2 nm to 500 nm, and morepreferably 5 nm to 200 nm.

When the polymer LED of the invention has a hole transporting layer, thehole transporting material to be used is exemplified with polyvinylcarbazole or its derivatives, polysilane or its derivatives,polysiloxane derivatives having aromatic amine in a side chain or mainchain thereof, pyrazoline derivatives, arylamine derivatives, stilbenederivatives, triphenyldiamine derivatives, polyaniline or itsderivatives, polythiophene or its derivatives, polypyrrole or itsderivatives, poly(p-phenylenevinylene) or its derivatives, andpoly(2,5-thienylenevinylene) or its derivatives.

The hole transporting material is specifically exemplified with thosedisclosed in Kokai S63-70257, S63-175860, H2-135359, H2-135361,H2-209988, H3-37992, and H3-152184.

Among them, the hole transporting material used for the holetransporting layer preferably includes high molecular weight holetransporting materials such as polyvinyl carbazole or its derivatives,polysilane or its derivatives, polysiloxane derivatives having anaromatic amine compound group in a side chain or main chain thereof,polyaniline or its derivatives, polythiophene or its derivatives,poly(p-phenylenevinylene) or its derivatives, andpoly(2,5-thienylenevinylene) or its derivatives; and more preferablypolyvinyl carbazole or its derivatives, polysilane or its derivatives,and polysiloxane derivatives having an aromatic amine in a side chain ormain chain thereof. When the hole transporting material is a lowmolecular weight, it is preferably used in a form dispersed in a polymerbinder.

The polyvinyl carbazole or its derivatives, for example, are producedwith cation or radical polymerization of a vinyl monomer.

The polysilane or its derivatives are exemplified with compoundsdisclosed in Chem. Rev. Vol. 89, page 1359 (1989) and the publishedspecification of British Patent GB2300196; and may be synthesized withmethods disclosed therein, and particularly preferably with Kippingmethod.

Since the polysiloxane or its derivatives hardly have holetransportability in their siloxane skeleton structure, they arepreferably used in the structure providing the above low molecular holetransporting material to their side chain or main chain; andparticularly exemplified with the structure providing a holetransporting aromatic amine to their side chain or main chain.

A method for forming a film of the hole transporting layer is notparticularly limited: as for the low molecular weight hole transportingmaterial, the method of forming a film from a solution thereof beingmixed with a polymer binder is exemplified; and as for the highmolecular weight hole transporting material, the method of forming afilm from a solution thereof is exemplified.

A solvent used for forming a film from the solution is not particularlylimited as long as dissolving the hole transporting material. Thesolvent is exemplified with the solvent used for the solutioncomposition of the invention.

The method for forming a film from a solution can use methods of coatingthe solution such as spin coat methods, casting methods, micro gravurecoat methods, gravure coat methods, bar coat methods, roll coat methods,wire-bar coat methods, dip coat methods, spray coat methods, screenprinting methods, flexographic printing methods, offset print methods,and inkjet methods.

The polymer binder to be mixed is preferably the one not significantlyinhibiting charge transportation, and furthermore the one not stronglyabsorbing visible light for being suitably applied. The polymer binderis exemplified with polycarbonates, polyacrylates, polymethylacrylates,polymethylmethacrylates, polystyrenes, polyvinyl chlorides, andpolysiloxanes.

An optimal film thickness of the hole transporting layer variesdepending on the materials used and may be set at the thickness ofmaking values of a driving voltage and emission efficiency reasonable;the thickness not causing a pinhole is at least required, while toothick film is unfavorable because of raising the driving voltage of adevice. Therefore, the film thickness of the hole transporting layer,for example, is 1 nm to 1 μm, preferably 2 nm to 500 nm, and morepreferably 5 nm to 200 nm.

When the polymer LED of the invention has the electron transportinglayer, known electron transporting materials can be used, and examplesthereof include oxadiazole derivatives, anthraquinodimethane or itsderivatives, benzoquinone or its derivatives, naphthoquinone or itsderivatives, anthraquinone or its derivatives,tetracyanoanthraquinonedimethane or its derivatives, fluorenonederivatives, diphenyldicyanoethylene or its derivatives, diphenoquinonederivatives, 8-hydroxyquinoline or its derivatives' metal complexes,polyquinoline or its derivatives, polyquinoxaline or its derivatives,and polyfluorene or its derivatives.

Specifically exemplified are those disclosed in Kokai S63-70257,S63-175860, H2-135359, H2-135361, H2-209988, H3-37992, H3-152184.

Among them, preferable are oxadiazole derivatives, benzoquinone or itsderivatives, anthraquinone or its derivatives, 8-hydroxyquinoline or itsderivatives' metal complexes, polyquinoline or its derivatives,polyquinoxaline or its derivatives, and polyfluorene or its derivatives;and more preferable being2-(4-biphenylyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole, benzoquinone,anthraquinone, tris(8-quinolinol)aluminium, and polyquinoline.

A method for forming a film of the electron transporting layer is notparticularly limited; as for a low molecular electron transportingmaterial, vacuum deposition methods from a powder and film formingmethods from a solution or molten state are exemplified; and as for ahigh molecular electron transporting material, film forming methods froma solution or molten state are exemplified. For forming a film from asolution or molten state, a polymer binder may be used together.

A solvent used for forming a film from a solution is not particularlylimited as long as dissolving an electron transporting material and/orpolymer binder. The solvent is exemplified with chlorine solvents suchas chloroform, methylene chloride, and dichloroethane; ether solventssuch as tetrahydrofuran; aromatic hydrocarbon solvents such as tolueneand xylene; ketone solvents such as acetone and methylethylketone; andester solvents such as ethyl acetate, butyl acetate, and ethylcellosolveacetate.

The methods for forming a film from a solution or molten state can usecoating methods including spin coat methods, casting methods, microgravure coat methods, gravure coat methods, bar coat methods, roll coatmethods, wire-bar coat methods, dip coat methods, spray coat methods,screen printing methods, flexographic printing methods, offset printmethods, and inkjet methods.

As the polymer binder to be mixed, preferable is the one notsignificantly inhibiting charge transportation, and furthermore the onenot strongly absorbing visible light for being suitably applied. Thepolymer binder is exemplified with poly(N-vinylcarbazole), polyanilineor its derivatives, polythiophene or its derivatives,poly(p-phenylenevinylene) or its derivatives,poly(2,5-thienylenevinylene) or its derivatives, polycarbonates,polyacrylates, polymethylacrylates, polymethylmethacrylates,polystyrenes, polyvinyl chlorides, or polysiloxanes.

An optimal film thickness of the electron transporting layer variesdepending on the materials applied and may be set at the thickness ofmaking values of a driving voltage and emission efficiency-reasonable;the thickness not causing a pinhole is at least required, while toothick film is unfavorable because of raising the driving voltage of adevice. Therefore, the film thickness of the electron transportinglayer, for example, is 1 nm to 1 μm, preferably 2 nm to 500 nm, and morepreferably 5 nm to 200 nm.

A substrate composing the polymer LED of the invention may be the onecapable of forming an electrode and not being changed informing anorganic film; for example, including glass, plastic, polymer film, andsilicone substrates. When the substrate is opaque, the oppositeelectrode is preferably transparent or translucent.

At least one of electrodes including an anode and cathode is typicallytransparent or translucent, and the electrode disposed at the anode ispreferably transparent or translucent. For a material of the anode,conductive metal oxide films, translucent metal thin films, and the likeare used: specifically including oxides such as indium oxide, zincoxide, tin oxide, and indium.tin.oxide (ITO) as a complex of suchoxides; films (NESA etc.) produced using an electrically conductiveglass which consists of indium.zinc.oxide, and the like; and gold,platinum, silver, copper, and the like; preferably ITO,indium.zinc.oxide, and tin oxide. A method for producing the electrodeincludes vacuum deposition methods, sputtering methods, ion platingmethods, plating methods, and the like. Moreover, the anode may useorganic transparent electric conductive films such as polyaniline or itsderivatives, polythiophene or its derivative, and the like. A filmthickness of the anode may be appropriately selected under considerationof optical transparency and electric conductivity, for example being 10nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to 500nm. Furthermore, on the anode, to make charge injection easy, a layermay be disposed, the layer being composed of a phthalocyaninederivative, a conductive polymer, carbon, or the like, or being composedof a metal oxide, metal fluoride, an organic insulating material, or thelike and having an average film thickness of 2 nm or less.

A material used for the cathode of the polymer LED of the invention ispreferably the material having small work function. For example, usedare metals such as lithium, sodium, potassium, rubidium, caesium,beryllium, magnesium, calcium, strontium, barium, aluminium, scandium,vanadium, zinc, yttrium, indium, cerium, samarium, europium, terbium,and ytterbium, and alloys composed of 2 or more thereof; alloys composedof one or more metal(s) or alloy(s) selected from the metal groupdescribed above and one or more metal(s) selected from the groupconsisting of gold, silver, platinum, copper, manganese, titanium,cobalt, nickel, tungsten, and tin; and graphite or intercalatedgraphites. Examples of the alloy includes magnesium-silver alloys,magnesium-indium alloys, magnesium-aluminium alloys, indium-silveralloys, lithium-aluminium alloys, lithium-magnesium alloys,lithium-indium alloys, calcium-aluminium alloys, and the like. Thecathode may be a layered structure having 2 or more layers.

A film thickness of the cathode may be appropriately selected underconsideration of electric conductivity and durability, for example being10 nm to 10 μm, preferably 20 nm to 1 μm, and more preferably 50 nm to500 nm.

A method for producing the cathode includes vacuum deposition methods,sputtering methods, laminating methods thermally bonding a metal thinfilm under a pressure, or the like. Furthermore, a layer may be disposedbetween the cathode and an organic substance layer, the layer beingcomposed of a conductive polymer, or being composed of a metal oxide,metal fluoride, an organic insulating material, or the like and havingan average film thickness of 2 nm or less; still furthermore, aprotection layer may be disposed to protect the polymer LED afterproducing the cathode. To use the polymer LED stably for long period andprotect a device from the outside, the protection layer and/orprotection cover is preferably disposed.

The protection layer may use high molecular weight compounds, metaloxides, metal fluorides, metal borides, and the like. The protectioncover may use glass plates, plastic plates of which surface is subjectedto anti-water permeability treatment, and the like; and a method ofadhering the cover with a device substrate with a thermally curableresin or light curable resin to seal is suitably employed. If a space onthe device is maintained by applying a spacer, it is easy to prevent thedevice from being harmed. If an inert gas such as nitrogen and argon issealed in the space, the cathode can be prevented from the oxidation;furthermore, if a desiccant agent such as barium oxide is disposed inthe space, the device can be easily protected from damages to be causedwith the water absorbed during the production processes. Any one or moremeans mentioned above is preferably applied.

The polymer light-emitting device of the invention can be used for flatlight sources, segment displays, dot-matrix displays, backlights forliquid crystal displays, and the like.

A flat light emission with using the polymer LED of the invention can beobtained by disposing a flat anode on a flat cathode. Furthermore, apatterned light emission can be obtained with methods such that a maskhaving a patterned window is disposed on the surface of the flatlight-emitting device mentioned above, that an organic substance layerof a part not emitting light is formed extremely thickly for making thepart substantially non-light-emitting, or that any one or both of thecathode and cathode is patterned. Forming a pattern with any one of theabove methods and arranging some electrodes which can be independentlyswitched, this can provide a segment-type display which is able todisplay numerals, letters, and simple marks. Furthermore, for providinga dot-matrix device, the anode and cathode are formed in a striped shaperespectively and arranged orthogonally each other. Selectively coatingplural kinds of polymer phosphors emitting different colors, or using acolor filter or fluorescence conversion filter, these methods enablepartially colored displaying or multi-colored displaying. The dot-matrixdevice is applicable to the passive drive, or may be applied to theactive drive under combination with TFT and the like. These displaydevices can be used for a display of computers, televisions, mobileterminals, cellular phones, car navigations, and a viewer finder ofvideo cameras.

Furthermore, since the flat light-emitting device mentioned above has athin shape and emits light by itself, it can be suitably used for a flatlight source for a backlight of liquid crystal displays, or for a lightsource of flat-shaped lamps; and still furthermore, being used forcurved light sources or displays by employing a flexible substrate.

With using the solution composition of the invention, coloring mattersfor lasers, materials for organic solar cells, organic semiconductorsfor organic transistors, and materials for electro conductive thin filmscan be produced.

Hereinafter, examples are illustrated to explain the invention in moredetail, but the invention should not be construed to be limited thereto.

Z-average molecular weight, number-average molecular weight, andweight-average molecular weight are determined with a gel permeationchromatography (GPC) (manufactured by Shimadzu Corporation: LC-10Avp) aspolystyrene-reduced Z-average molecular weight, number-average molecularweight, and weight-average molecular weight. A polymer to be measuredwas dissolved in tetrahydrofuran so as to become the concentration ofabout 0.5% by weight, and 50 μl of the polymer solution was injectedinto the GPC. The mobile phase of the GPC was tetrahydrofuran and flownby the flow velocity of 0.6 ml/min. A column was arranged by connectingtwo columns of TSKgel SuperHM-H (manufactured by TOSOH Co., Ltd.) andone column of TSKgel SuperH2000 (manufactured by TOSOH Co., Ltd.) inseries. A differential refractive index detector (manufactured byShimadzu Corporation: RID-10A) was used for a detector. The viscosity ofa composite was measured by the above method.

Synthesis Example 1 Synthesis of Polymer 1

After putting 12.8 g of the below compound A and 5.5 g of 2,2′-bipyridylin a reactor, the atmosphere of the reaction system was replaced withnitrogen gas. In the reaction system, 600 g of tetrahydrofuran(dehydration solvent) which was deaerated in advance by bubbling withargon gas, was added. Thereafter, in this mixed solution, 10 g ofbis(1,5-cyclooctadiene)nickel(0) was added, stirred at a roomtemperature for 10 minutes, and then reacted at 60° C. for 3 hours. Thereaction was conducted under the nitrogen gas atmosphere.

After the reaction, the resultant solution was cooled, poured into amixture of 80 ml of 25% aqueous ammonia/400 ml of methanol/400 ml ofion-exchanged water, and then stirred for about 1 hour. Then, theresultant precipitate was collected by filtration. This precipitate wasdried under a reduced pressure, and then dissolved in toluene. Afterfiltrating this toluene solution to remove insoluble matter, the toluenesolution was purified through a column packed with alumina. Thereafter,this toluene solution was washed with 1 N hydrochloric acid; andallowing stand still, and then subjected to partitioning separation torecover a toluene solution. Thereafter, this toluene solution was washedwith about 3% aqueous ammonia; and allowing stand still, and thensubjected to partitioning separation to recover a toluene solution.Thereafter, this toluene solution was washed with water; and allowingstand still, and then subjected to partitioning separation to recover atoluene solution. Thereafter, methanol was added to this toluenesolution with stirring to re-precipitate for purification.

Thereafter, the resultant precipitate was collected with filtration.This precipitate was dried under a reduced pressure to obtain 4.0 g ofpolymer. This polymer is referred to Polymer 1. Polymer 1 obtained hadpolystyrene-reduced Z-average molecular weight of 1.0×10⁶,weight-average molecular weight of 4.5×10⁵, and number-average molecularweight of 1.7×10⁵.

Preparation Example 1 Preparation of Composition 1

Composition 1 was prepared by dissolving 50 mg of Polymer 1 in a mixedsolution of 1.50 g of xylene and 3.53 g of bicyclohexyl. The polymerconcentration of Composition 1 is 0.98% by weight.

Example 1 Viscosity Measurement of Composition 1

The viscosity of Composition 1 was measured as 22.2 mPa·s.

Synthesis Example 2 Synthesis of Polymer 2

After putting 0.60 g of the above compound A and 0.37 g of2,2′-bipyridyl in a reactor, the atmosphere of the reaction system wasreplaced with nitrogen gas. In the reaction system, 40 g ofN,N-dimethylformamide (dehydration solvent) which was deaerated inadvance by bubbling with argon gas, was added. Thereafter, in this mixedsolution, 0.66 g of bis(1,5-cyclooctadiene)nickel(0) was added, stirredat a room temperature for 10 minutes, and then reacted at 60° C. for 3hours. The reaction was conducted under a nitrogen gas atmosphere. Afterfinishing the reaction, the reaction solution was cooled, poured into amixture of 10 ml of 25% aqueous ammonia/100 ml of methanol/200 ml ofion-exchanged water, and then stirred for about 1 hour. Thereafter, theresultant precipitate was collected by filtration. This precipitate wasdried under a reduced pressure, and then dissolved in toluene. Afterfiltrating this toluene solution to remove insoluble matters, thetoluene solution was washed with 1 N hydrochloric acid; and allowingstand still, and then subjected to partitioning separation to recoverthe toluene solution. Thereafter, this toluene solution was washed withabout 3% aqueous ammonia; and allowing stand still, and then subjectedto partitioning separation to recover the toluene solution. Thereafter,this toluene solution was washed with water; and allowing stand still,and then subjected to partitioning separation to recover a toluenesolution. Thereafter, methanol was added to this toluene solution withstirring to re-precipitate for purification.

Thereafter, the resultant precipitate was collected by filtration. Thisprecipitate was dried under a reduced pressure to obtain 0.15 g ofpolymer. This polymer is referred to Polymer 2. Polymer 2 obtained hadpolystyrene-reduced Z-average molecular weight of 4.2×10⁴,weight-average molecular weight of 2.2×10⁴, and number-average molecularweight of 1.0×10⁴.

Preparation Example 2 Preparation of Composition 2

Composition 2 was prepared by dissolving 50 mg of Polymer 2 in a mixedsolution of 1.51 g of xylene and 3.50 g of bicyclohexyl. The polymerconcentration of Composition 2 was 0.99% by weight.

Comparative Example 1 Viscosity Measurement of Composition 2

The viscosity of Composition 2 was measured as 2.6 mPa·s.

Synthesis Example 3 Synthesis of Polymer 3

After dissolving 0.48 g of the above compound A, 0.15 g of the belowcompound B, and 0.33 g of 2,2′-bipyridyl in 28 ml of dehydratedtetrahydrofuran, 0.58 g of bis(1,5-cyclooctadiene)nickel(0) was added tothis solution under a nitrogen atmosphere, heated up to 60° C., and thenreacted for 3 hours. After the reaction, the reaction solution wascooled to a room temperature, dropped into a mixture of 14 ml of 25%aqueous ammonia/170 ml of methanol/70 ml of ion-exchanged water, andthen stirred for about 30 minutes; thereafter, the resultant precipitatewas collected by filtration, dried under a reduced pressure for 2 hours,and then dissolved in 40 ml of toluene. 40 ml of 1 N hydrochloric acidwas added to this toluene solution, stirred for 3 hours, and thensubjected to fractionation to remove the water layer. Thereafter, theorganic layer was added with 40 ml of 4% aqueous ammonia, stirred for 3hours, and then subjected to fractionation to remove the water layer.Thereafter, the organic layer was dropped into 210 ml of methanol,stirred for 30 minutes, and then the resultant precipitate was collectedby filtration, dried for 2 hours under a reduced pressure to dissolve in40 ml of toluene. Thereafter, this toluene solution was purified througha column packed with alumina (14 g of alumina), and then the recoveredtoluene solution was dropped into 280 ml of methanol, stirred for 30minutes, and then the resultant precipitate was collected by filtrationto dry for 2 hours under a reduced pressure. The amount of the polymerobtained was 0.31 g. This polymer is referred to Polymer 3. Polymer 3obtained had polystyrene-reduced Z-average molecular weight of 1.0×10⁶,weight-average molecular weight of 3.7×10⁵, and number-average molecularweight of 7.6×10⁴.

Preparation Example 3 Preparation of Composition 3

Composition 3 was prepared by dissolving 51 mg of Polymer 3 in a mixedsolution of 1.51 g of xylene and 3.55 g of bicyclohexyl. The polymerconcentration of Composition 3 is 1.0% by weight.

Example 2 Viscosity Measurement of Composition 3

The viscosity of Composition 3 was measured as 6.2 mPa·s.

Synthesis Example 4 Synthesis of Polymer 4

After dissolving 0.48 g of the above compound A, 0.15 g of the abovecompound B, and 0.27 g of 2,2′-bipyridyl in ml of dehydratedtetrahydrofuran, 0.47 of bis(1,5-cyclooctadiene)nickel(0) was added tothis solution under a nitrogen atmosphere, heated up to 60° C., and thenreacted for 3 hours. After the reaction, the reaction solution wascooled to a room temperature, dropped into a mixture of 14 ml of 25%aqueous ammonia/170 ml of methanol/70 ml of ion-exchanged water, andthen stirred for 30 minutes; thereafter, the resultant precipitate wascollected by filtration, dried for 2 hours under a reduced pressure. Theamount of the polymer obtained was 0.5 g. This polymer is referred toPolymer 4. Polymer 4 obtained had polystyrene-reduced Z-averagemolecular weight of 3.9×10⁴, weight-average molecular weight of 2.5×10⁴,and number-average molecular weight of 1.3×10⁴.

Preparation Example 4 Preparation of Composition 4

Composition 4 was prepared by dissolving 51 mg of Polymer 4 in a mixedsolution of 1.51 g of xylene and 3.50 g of bicyclohexyl. The polymerconcentration of Composition 4 is 1.0% by weight.

Comparative Example 2 Viscosity Measurement of Composition 4

The viscosity of Composition 4 was measured as 2.3 mPa·s.

Synthesis Example 5 Synthesis of Compound C

After putting 5.00 g (29 mmol) of 1-naphthaleneboronic acid, 6.46 g (35mmol) of 2-bromobenzaldehyde, 10.0 g (73 mmol) of potassium carbonate,36 ml of toluene, and 36 ml of ion-exchanged water in a 300 mlthree-neck flask under an inert atmosphere, this mixture was bubbledwith argon gas for 20 minutes at a room temperature with stirring. Then,16.8 mg (0.15 mmol) of tetrakis(triphenylphosphine)palladium was addedto the mixture, and then further bubbled with argon gas for 10 minutesat a room temperature with stirring; thereafter, heated up to 100° C.,and then reacted for 25 hours. After being cooled to a room temperature,an organic layer was extracted with toluene, dried with sodium sulfate,and then distilled the solvent off. After being purified through asilica gel column with a mixed solution consisting of toluene:cyclohexane=1:2 as an eluent, 5.18 g (yield 86%) of Compound C wasobtained as a white crystal.

¹H-NMR (300 MHz/CDCl₃):

δ 7.39˜7.62 (m, 5H), 7.70 (m, 2H), 7.94 (d, 2H), 8.12 (d d, 2H), 9.63(s, 1H)

MS (APCI (+)): (M+H)⁺ 233

Synthesis Example 6 Synthesis of Compound D

After putting 8.00 g (34.4 mmol) of compound C and 46 ml of dehydratedTHF in a 300 ml three-neck flask under an inert atmosphere, this mixturewas cooled to −78° C. Then, to the mixture, 52 ml of n-octylmagnesiumbromide (1.0 mol/l THF solution) was dropped over 30 minutes. After thedropping, the resultant mixture was heated up to 0° C., stirred for 1hour, further heated up to a room temperature, and then stirred for 45minutes. Under placing the flask in an ice bath, the reaction wasterminated with addition of 20 ml of 1N hydrochloric acid, and then anorganic layer was extracted with ethyl acetate, and dried with sodiumsulfate. After distilling off the solvent, by purifying through a silicagel column with a mixed solution consisting of toluene:hexane=10:1 as aneluent, 7.64 g (yield 64%) of Compound D was obtained as a light yellowoil. Although two peaks were observed in a HPLC measurement, since theyhad the same mass number in a LC-MS measurement, they were judged as amixture of isomers.

Synthesis Example 7 Synthesis of Compound E

After putting 5.00 g (14.4 mmol) of compound D (the mixture of isomers)and 74 ml of dehydrated dichloromethane, in a 500 ml three-neck flaskunder an inert atmosphere, this mixture was stirred at a roomtemperature to dissolve. Then, boron trifluoride etherate complex wasdropped to the mixture at a room temperature over 1 hour, and then,after finishing the dropping, stirred at a room temperature for 4 hours.125 ml of ethanol was slowly added to the resultant mixture withstirring, and then, after the heat generation was finished, the organiclayer was extracted with chloroform, washed twice with water, and thendried with magnesium sulfate. By purifying through a silica gel columnwith hexane as an eluent, 3.22 g (yield 68%) of Compound E was obtainedas a colorless oil.

¹H-NMR (300 MHz/CDCl₃):

δ 90 (t, 3H), 1.03˜1.26 (m, 14H), 2.13 (m, 2H), 4.05 (t, 1H), 7.35 (dd,1H), 7.46˜7.50 (m, 2H), 7.59˜7.65 (m, 3H), 7.82 (d, 1H), 7.94 (d, 1H),8.35 (d, 1H), 8.75 (d, 1H)

MS (APCI (+)): (M+H)⁺ 329

Synthesis Example 8 Synthesis of Compound F

After putting 20 ml of ion-exchanged water in a 200 ml three-neck flaskunder an inert atmosphere, 18.9 g (0.47 mol) of sodium hydroxide wasadded little by little to dissolve with stirring. After the aqueoussolution was cooled to a room temperature, 20 ml of toluene, 5.17 g(15.7 mmol) of Compound E, and 1.52 g (4.72 mmol) of tributylammoniumbromide was added to the solution, and then heated up to 50° C.;thereafter, n-octyl bromide was dropped, and then, after finishing thedropping, reacted at 50° C. for 9 hours. After the reaction, the organiclayer was extracted with toluene, washed twice with water, and thendried with sodium sulfate. After distilling the solvent off, bypurifying through a silica gel column with hexane as an eluent, 5.13 g(yield 74%) of Compound F was obtained as a yellow oil.

¹H-NMR (300 MHz/CDCl₃):

δ 0.52 (m, 2H), 0.79 (t, 6H), 1.00˜1.20 (m, 22H), 2.05 (t, 4H), 7.34 (d,1H), 7.40˜7.53 (m, 2H), 7.63 (m, 3H), 7.83 (d, 1H), 7.94 (d, 1H), 8.31(d, 1H), 8.75 (d, 1H)

MS (APCI (+)): (M+H)⁺ 441

Synthesis Example 9 Synthesis of Compound G

After putting 4.00 g (9.08 mmol) of Compound F and 57 ml of the mixedsolvent consisting of acetic acid:dichloromethane=1:1 in a 50 mlthree-neck flask having a capacity of, under the air atmosphere, thismixture was stirred at a room temperature to dissolve. Thereafter, theresultant solution was added with 7.79 g (20.0 mmol) ofbenzyltrimethylammonium tribromide, and then, with stirring, zincchloride was added until benzyltrimethylammonium tribromide wascompletely dissolved. After stirring for 20 hours at a room temperature,the reaction was terminated with addition of 10 ml of 5% aqueous sodiumhydrogensulfite solution, and then the organic layer was extracted withchloroform, washed twice with aqueous potassium carbonate solution, andthen dried with sodium sulfate. After purifying twice through a flushcolumn with hexane as an eluent, by re-crystallizing with the mixedsolvent consisting of ethanol:hexane=1:1, and then with that of 10:1,4.13 g (yield 76%) of Compound G was obtained as a white crystal.

¹H-NMR (300 MHz/CDCl₃):

δ 0.60 (m, 2H), 0.91 (t, 6H), 1.01˜1.38 (m, 22H), 2.09 (t, 4H),7.62˜7.75 (m, 3H), 7.89 (s, 1H), 8.20 (d, 1H), 8.47 (d, 1H), 8.72 (d,1H)

MS (APPI (+)): (M+H)⁺ 598

Synthesis Example 10 Synthesis of Polymer 5 and 6

After dissolving Compound G (1.98 g, 0.0033 mol) and 2,2′-bipyridyl(1.39 g, 0.0089 mol) in 356 ml of dehydrated tetrahydrofuran, thissolution was bubbled with nitrogen to replace the atmosphere of thereaction system with nitrogen. Under the nitrogen atmosphere, thissolution was heated up to 60° C.,bis(1,5-cyclooctadiene)nickel(0){nickel(COD)₂} (1.392 g, 0.0089 mol) wasadded, and then reacted for 3 hours. After the reaction, the reactionsolution was cooled to a room temperature (about 25° C.), dropped intothe mixed solution consisting of 12 ml of 25% aqueous ammonia/350 ml ofmethanol/350 ml of ion-exchanged water, stirred for 30 minutes, and thenthe resultant precipitate was collected by filtration and dried withair. Thereafter, the precipitate was dissolved in 100 ml of toluene, andthen subjected to filtration; thereafter, the filtrate was purifiedthrough an alumina column, added with about 200 ml of 1N hydrochloricacid, stirred for 3 hours, and then the water layer was removed;thereafter, about 200 ml of 4% aqueous ammonia was added to the organiclayer, and then stirred for 2 hours to remove the water layer. About 200ml of ion-exchanged water was added to the organic layer, and stirredfor 1 hour, the water layer was removed. About 50 ml of methanol wasdropped to the organic layer, stirred for 1 hour, and then thesupernatant liquid was separated by filtration. The precipitate obtainedby these procedures is referred to I and the filtrate is referred to II.

Precipitate I obtained was dissolved in 100 ml of toluene, dropped inabout 200 ml of methanol, stirred for 1 hour, filtrated, and then driedfor 2 hours under a reduced pressure. The amount of the polymer obtainedwas 2.6 g (hereinafter, referred to Polymer 5). The polystyrene-reducedaverage molecular weight and the weight average molecular weight ofPolymer 5 were Mn=7.4×10⁴, Mw=1.8×10⁵, and Mz=3.4×10⁵ respectively.

Moreover, Filtrate II was condensed to 10 ml with an evaporator, droppedin about 50 ml of methanol, stirred for 1 hour, and then filtrated todry for 2 hours under a reduced pressure. The amount of the polymerobtained was 0.08 g (hereinafter, referred to Polymer 6). Thepolystyrene-reduced average molecular weight and the weight averagemolecular weight of Polymer 6 were Mn=9.3×10³, Mw=1.4×10⁴, andMz=2.3×10⁴ respectively.

Preparation Example 5 Preparation of Composition 5

Composition 5 was prepared by dissolving 51 mg of Polymer 5 in a mixedsolution of 1.50 g of xylene and 3.51 g of bicyclohexyl. The polymerconcentration of Composition 5 was 1.0% by weight.

Example 3 Viscosity measurement of Composition 5

The viscosity of Composition 5 was measured as 7.0 mPa·s.

Preparation Example 6 Preparation of Composition 6

Composition 6 was prepared by dissolving 51 mg of Polymer 6 in a mixedsolution of 1.52 g of xylene and 3.50 g of bicyclohexyl. The polymerconcentration of Composition 6 is 1.0% by weight.

Comparative Example 3 Viscosity Measurement of Composition 6

The viscosity of Composition 6 was measured as 2.0 mPa·s.

INDUSTRIAL APPLICABILITY

The solution composition of the invention can have a significantly highviscosity and a film having high uniformity can be easily obtained. Thepolymer light-emitting device including the film of high uniformity as alight-emitting layer can be used for flat light sources, segmentdisplays, dot-matrix displays, back-lights for liquid crystal displays,and the like.

1. A solution composition comprising one or more solvent(s) and one ormore conjugated aromatic polymer(s) having a polystyrene-reducedZ-average molecular weight of 1.0×10⁵ to 5.0×10⁶, and having at leastone repeating unit selected from the group consisting of formulas (1-1)and (1-2), and an amount of a repeating unit other than the formulas(1-1) and (1-2) is 30% by moles or less based on the sum of totalrepeating units:

wherein A ring, B ring, C ring, and D ring each independently representan aromatic ring; and X represents —O—, —N(R)—, —Si(R)₂, —Se—, B(R)—,—S—, —S(═O)—, —SO₂—, —P(═O)(R)— or —P(R)—, wherein R represents an alkylgroup, an alkoxy group, an alkylthio group, an alkylsilyl group, analkyl amino group, a hydroxyl group, an amino group, a carboxyl group,an aldehyde group, a cyano group, an aryl group, an aryloxy group, anarylthio group, or an arylalkyl group.
 2. The solution compositionaccording to claim 1, wherein the one or more conjugated aromaticpolymer(s) has at least one repeating unit represented by formula (1-1).3. The solution composition according to claim 1, wherein X is —S— or—O—.
 4. The solution composition according to claim 3, wherein X is —S—.5. The solution composition according to claim 1, wherein the polymerhas a polystyrene-reduced number-average molecular weight of 5.0×10⁴ to3.0×10⁵, polystyrene-reduced weight-average molecular weight of 1.0×10⁵to 1.0×10⁶, and polystyrene-reduced Z-average molecular weight of3.0×10⁵ to 3.0×10⁶.
 6. The solution composition according to claim 1,wherein the polymer content is 0.5 to 1.5% by weight when the totalweight of the solution composition is defined as 100% by weight.
 7. Thesolution composition according to claim 1, comprising two or more kindsof solvents.
 8. A thin film produced with using the solution compositionaccording to claim
 1. 9. A polymer light-emitting device having alight-emitting layer between electrodes comprising an anode and acathode, wherein the light-emitting layer is formed with using thesolution composition according to claim
 1. 10. The polymerlight-emitting device according to claim 9, wherein the light-emittinglayer is formed by inkjet method.
 11. A flat light source comprising thepolymer light-emitting device according to claim
 9. 12. A segmentdisplay comprising the polymer light-emitting device according to claim9.
 13. A dot-matrix display comprising the polymer light-emitting deviceaccording to claim
 9. 14. A liquid crystal display comprising thepolymer light-emitting device according to claim 9, as a backlight.